Although hidden from plain sight, groundwater is an integral part of our everyday life. As you would expect, aquifers, freshwater springs and hot springs are also a part of groundwater. A large percentage of valley residents rely on groundwater for drinking water and household purposes. The stone spouts and wells that we see today as mostly decoration were important access points to extract groundwater for drinking water, washing clothes, washing vegetables and cooking. This is the earliest example of extraction of groundwater in the valley, started by the Licchavi rulers. In the words of Mr Suresh Uprety, a consultant hydro- geologist “Jata Mul Cha, Teta Basti Huncha” (settlements are decided on the basis of the availability of water sources), these wells and stone taps were a shared water resource within different communities.
In 1890, Rana Prime Minister Bir Shumsher ordered the construction of modern taps which supplied water from the Shivapuri hills to Kathmandu valley. By the end of 1950s, the last Rana Prime Ministers and other rulers expanded private taps. Slowly, spout water and wells were abandoned by the population as groundwater was considered unsanitary.
But as the population of Kathmandu expanded rapidly, approximately 2.5 times purely within the last decade, water demand within the valley from households and industries continued to rise. Kathmandu valley is situated upstream of the Bagmati River Basin (BRB). The basin is also vulnerable to environmental change and pollution. Pollution and environmental degradation through mixing of industrial/ household waste and sewage into the river has changed BRB immensely. Of course, we have all heard stories of the Bagmati River in Kathmandu turning from a pristine river people used to swim in and drink water to becoming a river most people can’t even stand next to. Such factors have put significant stress on the BRB’s ecology and brought negative impacts to it. The ecosystem also lacks the resilience and adaptive capacity to cope with such large changes in such a short time.
Since fresh water is so susceptible to pollution and cannot fulfill the valley’s growing demand for water, even now, groundwater supplies an estimated half of total water supply during wet season and around 60 -70% during dry season in Nepal.
In an industrial scale, Nepal Water Supply Corporation first extracted groundwater using a submersible pump in 1970. In 1984, the corporation extracted 9 million megalitres (mld) of water per day, this figure then quadrupled to 34 mld per day by 1998. In 1998, the water consumption had increased by five folds with deep tube wells, shallow tube wells, stone taps, open wells and spring sources withdrawing 42 mld water per day.
Groundwater recharge can occur in various ways in order for underground aquifers to replenish. Rainfall, water flowing into the ground from rivers, water seeping into the ground from ponds, lakes, canals or excess irrigation are some examples of groundwater recharge. According to Mr Suresh Uprety, groundwater withdrawal is not the problem, but its management is. As of now, groundwater is being extracted by individual households, hotels, industries, housing complexes etc without proper planning or consideration. Thus, withdrawal exceeds recharge. A 1999 study estimated that the groundwater extracted per day was 58.6 mld. This was labeled an over exploitation by 60% at the time. It is also estimated that if the extraction of groundwater continues at the same level as it did in 2001 (i.e 59.6 mld), shallow and deep aquifers will be drained in less than 100 years.
Furthermore, the quality of groundwater is deteriorating due to insufficient institutional responsibility in monitoring its use. In many parts of Nepal but especially Kathmandu, groundwater is contaminated by seepage from septic tanks and soakways. Use of ammonium based fertilizers or other pollution leads to high Ammonium concentrations in groundwater. Improper disposal of domestic or industrial wastes can contaminate water with e-coli which is harmful to human health as well as nitrates, arsenic, excess iron and heavy metals.
Depletion of groundwater levels can lead to water scarcity in the city especially as the population grows rapidly and crops lack adequate resources for irrigation. Groundwater mining can cause the lowering of piezometric head and clay and silt layers of the earth’s surface. This can cause land subsidence which puts settlements in danger especially during earthquakes that Nepal is prone to. This subsidence, in turn, shrinks the total volume of aquifers and underground water storage.
Now on the subject of recharge, the Department of Hydrology and Meteorology states that Kathmandu has a catchment area of 656 sq km. (Here, catchment area refers to the land where water collects after rain, it is typically surrounded by hills and can replenish groundwater). Kathmandu valley receives 1500 mm rainfall annually. Currently, the valley has the recharge of 9.6 million cubic metres per year. Several studies conducted within the last five decades within hydrogeology, ground water availability and groundwater quality suggest that if rain water could be efficiently harvested, especially in the monsoon season, it could increase the amount of supply of groundwater and recharge the valley’s aquifers to a great extent. On an individual level, it is estimated that 80% of Nepali households are capable of harvesting rainwater.
Shrinking of open spaces, lack of rainfall, pitching roads, open spaces and paving garden spaces in homes with concrete are some reasons rainwater cannot enter the ground into aquifers. It is recommended that infrastructures like roads, parks and yards should be constructed with the intent of supporting and accommodating greenery but also with materials that allow water absorption.
In a study “Identification of critical locations for enhancing groundwater recharge in Kathmandu Valley, Nepal”, it was stated that northern and southern regions of Kathmandu can play an important role in recharging groundwater as they have lower runoff rates. This means the land there can absorb more water that can refill groundwater as compared to eastern and western parts of the valley with higher runoff rates.
It is estimated that a total of 1.6 million citizens will not have access to water by the year 2050 even after the successful completion of the Melamchi Water Supply Project. Focusing on recharging aquifers now can help to make water more accessible for Nepalese citizens. Besides this, groundwater recharge can help prevent floods during the monsoon season, preclude land subsidence and restore wells, ponds, springs and other sources of water.
Another way to recharge ground water can be artificial and managed aquifer recharge. However, this requires a lot of research and management and is yet to be introduced in Nepal. A ‘groundwater use action plan’ was issued by the Supreme Court in 2009 for the entire country. The policy proposes an amendment to the 1992 water resources act inorder to control unplanned groundwater extractions and balance it with recharge programmes, promoting rainwater harvesting and protecting groundwater quality. The Kathmandu Valley Water Supply Management Board (KVWSMB) submitted the policy as a draft to the Ministry of Physical Planning and Works in 2010. Since 2009, initiatives like knowledge sharing, national symposiums and expert meetings on managing and conserving groundwater have played a role in raising awareness about the current groundwater situation in Nepal among the public and responsible authorities.
Moving on to the growing demand of the valley, the Centre for Integrated Urban Development (CIUD), along with WaterAid Nepal is implementing groundwater recharge by a rainwater project at the Rajdal Army Barrack of Lalitpur Metropolitan City. The project aims to provide a reliable and sustainable system to inhabitants of the valley and raise awareness about the importance of groundwater recharge at a municipal level. The organizations are working towards building 48 recharge wells inside the barrack and recharge 51,000 kiloliters of rainwater into the ground annually.
Besides this, a little insight outside of the valley, the Peace Winds Japan, a Japanese NGO has been working towards constructing water supply facilities in Sindhupalchowk district. This is a project supported by the Government of Japan under the Grant Assistance for Japanese NGO project schemes. The project aims to improve access to water and support agriculture along with providing training provision to local people so that they can operate the water supply facilities independently and ensure the longevity of the initiative. The initiative is titled “the Project for Improving Water Access and Agriculture Income”, the ambassador of Japan to Nepal, Mr Kikuta Yutaka visited the Balefi Rural Municipality in Sindhupalchowk to participate in the handover ceremony of the project.